4.1.3 Excavation and Disposal
4.1.3.1 Excavation and Disposal for Soil
4.1.3.2 Excavation and Disposal for Weathered Rock
4.1.3.3 Excavation and Disposal for Normal Rock
4.1.4 Backfilling by excavated materials
4.1.5 Concrete Box Culvert
4.1.5.1 Mass Concrete for foundation and backfill